Conventionally, in a lithography process for manufacturing electronic devices (microdevices) such as liquid crystal display devices and semiconductor devices (integrated circuits and the like), used are exposure apparatuses such as an exposure apparatus of a step-and-scan method (a so-called scanning stepper (which is also called a scanner)) that, while synchronously moving a mask (a photomask) or a reticle (hereinafter, generically referred to as a “mask”) and a glass plate or a wafer (hereinafter, generically referred to as a “substrate”) along a predetermined scanning direction (scan direction), transfers a pattern formed on the mask onto the substrate using an energy beam.
As this type of exposure apparatuses, such an exposure apparatus is known that is equipped with an optical interferometer system that obtains the position information of a substrate serving as an exposure target, within a horizontal plane, using a bar mirror (a long mirror) that a substrate stage device has (e.g., refer to PTL 1).
Here, in the case of obtaining the position information of a substrate using the optical interferometer system, the influence of so-called air fluctuation cannot be ignored. Further, although the influence of air fluctuation can be reduced by using an encoder system, it is difficult to prepare a scale that can cover the entire movement range of the substrate due to the increase in size of the substrate in recent years.